The present invention relates to refrigeration systems and more particularly to a refrigeration system useful in a domestic refrigerator of the type having separate chilling and freezing compartments.
Environmental concerns are providing an impetus for, on the one hand, household refrigerators that are more energy efficient and, on the other hand, refrigeration systems which do not employ ozone-deleterious refrigerants. Unfortunately, in conventional refrigerator designs, these two considerations are to some extent contradictory. In order to provide the low temperatures required for storing frozen foods, a high compression ratio is needed necessitating a refrigerant such as R-12. This refrigerant has a high ozone depletion factor. The desirable refrigerants from the point of view of ozone depletion, e.g. R-22, are not well suited to low temperature refrigeration, i.e. applications where sub zero temperatures are needed, because they are not suited for high compression ratios.
Among the several objects of the present invention may be noted the provision of a refrigeration system which facilitates the use of low compression ratio refrigerants; the provision of such a refrigeration system which is very energy efficient; the provision of such a refrigeration system which is well suited for utilization in domestic refrigerators; the provision of such a refrigeration system which will facilitate the providing of two independent suction temperatures; the provision of such a refrigeration system which is highly reliable and which is of relatively simple and inexpensive construction. Other objects and features will be in part apparent and in part pointed out hereinafter.